Multiple choice

A chemical production company dilutes a chemical by mixing it with water. The new mixture of 170 litres contains chemical and water in 27 : 7 proportion. Later, the company decides to further dilute the mixture to form a new mixture containing chemical and water in 3 : 1 proportion. How much water must they add in the previous mixture?

  1. 10 litres

  2. 7.5 litres

  3. 5 litres

  4. 12 litres

  5. 15 litres
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Initial mixture: 170 liters, 27:7 ratio. Chemical = (27/34)*170 = 135, Water = (7/34)*170 = 35. To get 3:1 ratio, 135 / (35 + x) = 3 / 1. Solving gives 135 = 105 + 3x, so 3x = 30, x = 10.

AI explanation

In the 170 liter mixture, the initial amount of chemical is (27 / 34) * 170 = 135 liters and water is 35 liters. To achieve a chemical to water ratio of 3 to 1, the 135 liters of chemical must be three times the new volume of water. Dividing 135 by 3 gives a required water volume of 45 liters, so the company must add 10 liters of water to the initial 35 liters.

Keep practicing — related questions